Returns an indexed property descriptor for the class that matches the property name. - Java Reflection

Java examples for Reflection:Property

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Description

Returns an indexed property descriptor for the class that matches the property name.

Demo Code

/*/*from   w  w  w.j ava  2s .c om*/
 * Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
//package com.java2s;

import java.beans.IndexedPropertyDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;

import java.beans.PropertyDescriptor;

public class Main {


    /**
     * Returns an indexed property descriptor for the class
     * that matches the property name.
     *
     * @param type  the class to introspect
     * @param name  the name of the property to search
     * @return the {@code IndexedPropertyDescriptor}
     */
    public static IndexedPropertyDescriptor getIndexedPropertyDescriptor(
            Class type, String name) {
        PropertyDescriptor pd = findPropertyDescriptor(type, name);
        if (pd instanceof IndexedPropertyDescriptor) {
            return (IndexedPropertyDescriptor) pd;
        }
        reportPropertyDescriptor(pd);
        throw new Error("could not find indexed property '" + name
                + "' in " + type);
    }

    /**
     * Finds a property descriptor for the class
     * that matches the property name.
     *
     * @param type the class to introspect
     * @param name the name of the property to search
     * @return the {@code PropertyDescriptor}, {@code IndexedPropertyDescriptor} or {@code null}
     */
    public static PropertyDescriptor findPropertyDescriptor(Class type,
            String name) {
        PropertyDescriptor[] pds = getPropertyDescriptors(type);
        for (PropertyDescriptor pd : pds) {
            if (pd.getName().equals(name)) {
                return pd;
            }
        }
        return null;
    }

    /**
     * Reports all the interesting information in an Indexed/PropertyDescrptor.
     */
    public static void reportPropertyDescriptor(PropertyDescriptor pd) {
        System.out.println("property name:  " + pd.getName());
        System.out.println("         type:  " + pd.getPropertyType());
        System.out.println("         read:  " + pd.getReadMethod());
        System.out.println("         write: " + pd.getWriteMethod());
        if (pd instanceof IndexedPropertyDescriptor) {
            IndexedPropertyDescriptor ipd = (IndexedPropertyDescriptor) pd;
            System.out.println(" indexed type: "
                    + ipd.getIndexedPropertyType());
            System.out.println(" indexed read: "
                    + ipd.getIndexedReadMethod());
            System.out.println(" indexed write: "
                    + ipd.getIndexedWriteMethod());
        }
    }

    /**
     * Returns an array of property descriptors for specified class.
     *
     * @param type  the class to introspect
     * @return an array of property descriptors
     */
    public static PropertyDescriptor[] getPropertyDescriptors(Class type) {
        try {
            return Introspector.getBeanInfo(type).getPropertyDescriptors();
        } catch (IntrospectionException exception) {
            throw new Error("unexpected exception", exception);
        }
    }
}

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